


Little Brother

by idkspookystuff



Category: Supernatural
Genre: Angst, BAMF Castiel, Brother AU, Castiel is a Winchester, F/M, Fallen Angel Castiel, Family, Human Castiel, Teenage Castiel, Teenage Dean Winchester, Teenage Sam Winchester
Language: English
Status: Completed
Published: 2015-06-12
Updated: 2015-06-12
Packaged: 2018-04-04 02:08:36
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,692
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4122130
Author URL: https://archiveofourown.org/users/idkspookystuff/pseuds/idkspookystuff
Summary: <blockquote class="userstuff">
              <p>When John finds a baby on a hunt, he decides to keep the child for his own safety. Castiel Winchester quickly blends in with the Winchesters.<br/>There's nothing different about Castiel that Sam, Dean, and John notice until Sam and Dean go on a mission to find their father and brother after they go missing. However, when they finally do find Castiel, they learn one major thing about him: he's an angel.</p>
            </blockquote>





	Little Brother

**Author's Note:**

> This was written for the [spnhiatuscreations](http://spnhiatuscreations.tumblr.com/) on tumblr. The prompt was BAMF!Castiel and I kind of took it and ran. I'm really proud of this so make sure you tell me what you think!  
> Also follow me[on tumblr](http://choirboycas.tumblr.com/) because i'm really cool

It was a cold winter’s day in Lawrence, and at two in the morning in the tiny home of John and his boys, the only sounds that could be heard were the soft snores of the two young brothers, who had been fast asleep for quite some time.

Or one of them had, at least.

Dean, at eight years old, was wide awake in his bed, watching his four year old brother sleep soundly, lit only by the moonlight shining through their window, and the headlights of an occasional truck, just passing through, not giving Lawrence a second thought. Dean couldn’t sleep. Though Sammy had no idea what their father was up to, Dean did. He knew that his father had went out to hunt a monster, and it always scared Dean that he didn’t know if his dad would come home safe or not.

The wooden front door to the tiny house squeaked open, altering Dean of his father’s return. He quickly hopped out of bed and ran over to the door to greet his father. The older hunter walked through the entrance way holding something in his arms. “What’s that?” Dean whispered, alerting the older hunter of his presence.

“The nest must have taken him. I found him all by himself, poor thing.” John leaned down to let Dean see the baby in his arms. He was wrapped in a blanket and looked absolutely shaken. Dean was mesmerized by the child’s eyes. They were a bright blue color that seemed to burn right into his soul. “Can we keep him?”

John laughed softly at his son’s innocence, standing upright. “If we can’t find his parents, I feel like we’ll have to.” He looked over at the clock next to him, alerting him of the late hour. _Midnight._ “Go sleep with your brother, young man.”

That night, John put the young baby to sleep next to the two brothers. Dean found himself still unable to sleep and so he very carefully climbed from bed, tiptoeing over to the baby. He was still awake as well, his eyes wide open, but he wasn’t crying or screaming like Sammy did when he was little. He was just staring at Dean, his wide, blue eyes piercing Dean’s. Dean reached out for the baby and smiled as the baby reached back for him. Instead of grabbing Dean’s finger, he put his hand against Dean’s arm, and the young boy felt a sharp sting.

The next morning, when Dean woke up, he had a burn on his arm. Thinking it was probably just from when he was trying to cook for Sammy, he brushed it off and ran downstairs to get breakfast.

 He didn’t realize it was in the shape of a handprint.

-

John called every family in the area, but none of them had been missing a tiny child. No hospitals had one missing, and all of the orphanages reassured him that they hadn’t lost a child. He couldn’t leave the little one with one of the orphanages. He wasn’t sure who was out for the baby, or what their intentions were.

And so Dean and Sammy got a younger brother. Sammy decided to name him Castiel, because Castiel was the angel of Thursdays. “And,” Sammy explained, his smile wide enough to show the gaps in his teeth, “We got ‘im on a T’ursday and his eyes look li’e an angel!”

It was decided as simple as that. Castiel would grow up as a Winchester, being trained alongside them, going to school alongside them. They even gave him their last name. Castiel Winchester, the family decided, flowed quite nicely.

-

It happened for the first time when Castiel was five.

Dean, who was thirteen now and had better things to do than train a nine and nine year old how to fight, was doing just that. Dad had told him that protecting his family was more important than the date he had. He obviously didn’t see the girl Dean managed to score this time. Meg was walking eye candy. Dad was obviously blind or unfair with the cruelty of a dictator.

Being as pissed as he was, Dean wasn’t paying close attention to his sibling’s training. His rules were simple: _try to break four blocks on top of each other._ If Dean was being honest with himself, he was pretty smug about this plan. He was positive that it was impossible to break that many. Sammy had been going at it for a while when Dean decided to lay on the ground. He closed his eyes and started to think about all the things he could be doing with Meg when Sammy shouted out in surprise.

Dean quickly rushed to his feet to see what was wrong. First, he checked that neither of his siblings had been hurt. Upon seeing that neither had, he looked at the ground where both of their eyes were pointed. In front of Castiel’s little feet were four broken wooden blocks. “He just broke them all!” Sammy exclaimed, his voice more in awe that in wonder like Dean was. How the _hell_ had he managed that?

“Um,” Dean looked down at the blocks, and then back up at his brothers’ smiling faces. Maybe it was just a freak thing? “Yeah. Let’s just try it again.

-

Dad was gone the day of the high school’s prom.

A lot was different now. For one, Sammy didn’t go by Sammy anymore. He was Sam, and he was eighteen, and tonight was the night of his senior prom. Castiel had gone from being the strongest kid ever to a shy, quiet, and careful fourteen year old. It was his first prom as a freshmen, and while Sam had gone in a group of nerds his age, Castiel managed to score a date. Hannah Milton was smart, funny, and adorable. She seemed really into Castiel, too, and Dean knew how excited his younger brother was.

The twenty-two year old high school dropout was lying in bed, headphones in and listening to whatever Journey song was popular in 2001, when he heard it. Sniffling, coming from Castiel’s room. Dean looked at the clock, which showed that the fourteen year old should have left hours before, and hopped out of bed, quickly making his way over to Castiel’s room.

He pushed the door open slowly and found Castiel crying in the corner, his back to the door. He was still wearing the suit he had insisted on wearing, and in his hands was the corsage he had bought for Hannah. “Hey dude,” Dean said gently. “What happened?”

“Hannah stood me up,” Castiel said softly, not turning to face his older brother. Dean exhaled, sitting next to Castiel. He ran a hand up his brother’s back comfortingly. “She texted me and said ‘why would I want to go to prom with a freak?’”

“Aw, dude.” Dean pulled Castiel into a tight hug, letting his younger brother cry against his shoulder.

“Why don’t girls like me, Dean?”  Castiel asked, looking up at Dean. “Am I a freak?”

“Of course not, bud.” Dean answered. He pulled away from his brother and used the sleeve of his flannel to wipe the boy’s tears. “You know what? She didn’t deserve you.”

“She didn’t?” Castiel asked softly.

“Of course not.” Dean said, whipping the tears from Castiel’s eyes. He smiled at his younger brother. “Now, come on. Let’s go watch some movies and forget that dumb bitch.”

-

Sam went off to Stanford with a screaming match with John.

Dean drove his younger brother to the college with a dufflebag over his shoulder. “Sam, man, I-“

“Why do you listen to him, Dean?” Sam asked, turning towards Dean. “Why do you let him treat you like you’re a ragdoll? Like you’re his toy that he can just use to fuck you over again and again. Do you want this to be your life, Dean?”

“You know what, Sam, it is my life!” Dean answered, throwing his hands down on the steering wheel. “It’s bullshit and I didn’t sign up for it, but it’s what you do. Dad, he’s family. When family needs you, you’re there, even if it’s fucked up.” When Sam didn’t answer, Dean added. “He’s your father, dude.”

“Yeah,” Sam huffed, throwing his bag over his shoulder. “Not so much.” And with that, Sam was gone, off to college, not to be seen by Dean ever again.

Or so he thought.

-

Four years later, Dean shows up in Sam’s apartment.

It took a lot of convincing on Dean’s part, but eventually he had Sam and his girlfriend Jessica, a beautiful blonde who was definitely _way_ out of Sam’s league, staring at him. “Dad and Cas haven’t been home in a few days.”

“So?” Sam asked, his expression unchanging. “They’re working overtime on a Miller Time shift. They’ll stumble back in sooner or later.”

Dean ducked his head and tried to figure out how to explain to Sam how serious it really was without concerning his girlfriend. “Dad and Cas are on a hunting trip,” he eventually decided, “And they haven’t been home in a few days.”

Sam’s expression remained unchanging as he turned to his girlfriend. She glanced up at him with concern written across her face. “Jess, excuse us,” Sam started. “We have to go outside.”

-

“You’re not hearing me, Sammy,” Dean argued, deliberately not paying attention as his brother’s face changing at the nickname. “Dad and Cas are missing. I need you to help me find them.”

Sam huffed, following Dean down the stairs. “Dad’s always missing,” he said, pulling a sweatshirt over his head to protect himself from the cold. “You remember the poltergeist in Amherst? Or the Devil's Gates in Clifton? He was missing then, too. He's always missing, and he's always fine.”

Dean stopped and turned to face his brother. Sam stopped in tandem. “Not for this long. Now are you gonna come with me or not?”

-

That night, Dean dropped Sam back off at Stanford. He had some fancy law school interview the next morning. Dean was proud of him, he really was. He just had the feeling that something wasn’t right. The hunt had been too easy. They never had a win without backlash.

Suddenly, Sam’s apartment burst into flames. Dean tried to run in, but it was too late. Eventually, the street was flooded with firetrucks and bad news. Sam’s girlfriend had died in the fire. He couldn’t save her in time.

Dean crossed around to the back of the car, where Sam was loading a shotgun into the trunk. Before Dean even had the chance to ask, “Are you okay?” Sam was speaking. “Come on,” He said, slamming the trunk of the car. “We got work to do.”

-

Eventually, after months and months of hunting, research, and following an empty trail, Dean and Sam had a lead on their younger brother.

There were reports of a group of dead bodies showing up all around a town, always left behind by a teenager. He was described as average height, average weight, brown hair and the brightest blue eyes anyone had ever seen in their life. And the weirdest part was that he would always disappear, vanish in thin air, as the bodies were found.

They came across a barn where Castiel was reported to show up often and waited. Suddenly, there was a bolt of lightning. The doors creaked open and a shadow walked through. Not seeing who it was, Sam and Dean began to shoot at it, to no avail. The creature just kept walking closer and closer to them.

Suddenly, they came face to face with their youngest brother. “Sam?” He asked, tilting his head to the side in confusion. “Dean?”

“Cas, man,” Dean said, grabbing his younger brother by the arm. “You’ve got some explaining to do.”

-

In a hotel room in a shitty part of town, Castiel told Sam and Dean everything.

“Dad had sent me out to get supplies,” he started, easily slipping into the story.

_“Hello?” Castiel called into the empty hotel room. There was broken glass all over the room, and the curtains covering the window were blowing softly in the wind._

_On the table was a note that Castiel recognized to be his father’s sloppy handwriting._

Castiel pulled a bent up piece of paper out of his pocket and handed it to his oldest brother. “Cas,” Dean read out loud. “Don’t try to find me. Go find Sam and Dean.” He sighed, throwing the note down on the table. “Well that’s fucking great. Do you know where he could be?”

“No,” Castiel answered softly, taking the cup of tea that Sam offered him. “I tried to locate him, but my conquest was fretless.” He took a long sip of the tea in his hands before continuing. “However, it was in a field that I first encountered them.”

“Who?” Dean asked quickly.

_A group of men and women in suits had Castiel surrounded in the abandoned park. “W-who are you?” Castiel asked, his voice shaking._

_“Don’t you remember?” One of the women asked Castiel, her voice soft though her expression was threatening. “We are your brothers and sisters.” She ran her hand up a blade. “Or, well, we were.”_

_“I don’t have any family,” Castiel said quickly, backing into one of the men. “Not any really family, anyway.”_

_“Silly, silly boy.” One of the angels said. “Would you like to hear one of my favorite stories?” When there was no reply from Castiel, he continued. “A little angel was foolish and thought he wanted to be human, so he pulled out his grace and fell from Heaven. He thought he was safe before he ran into a group of angels. Silly, silly boy.”_

_“What-“Castiel started, taking a deep breath. “What happened to him?”_

_The man shot Castiel a menacing look. “He died.”_

_A woman chuckled softly. “And guess who we are, Castiel,” She said, drawing the boy’s name out._

_“Who are you?” The boy asked in tandem._

“Angels,” Castiel finished the story, looking up at his brothers, who were staring back at Castiel with an expression that was equal parts confusion and horror. “They were angels. And so am I.”

-

When they found their father, everything went to hell.

Suddenly, it was Castiel’s responsibility to be in charge. His father was in the passenger seat next to him, holding his wound and occasionally groaning in pain. Sam and Dean were slumped on top of each other, unconscious, in the back. Castiel had never seen his father nor brothers in this state. It was new, frightening, and still so _human_.

“Look, just hold on, alright,” Castiel said to his father, trying to offer the older hunter some comfort. “The hospital’s only ten minutes away.”

“I’m surprised at you, Castiel,” John said, looking over at his son. “Why didn’t you kill it? I thought we saw eye-to-eye on this? Killing this demon comes first. Before me, before everything.”

Castiel looked back at his brothers. They meant everything to him. “No, sir. Not before everything. Look, we’ve still got the Colt. We still have the one bullet left. We just have to start over, alright? I mean, we already found the demon-“

Castiel never got to finish his list as an eighteen wheeler truck rammed into the front of John’s car, knocking them all out.

-

When Dean came to, he couldn’t remember any of his surroundings.

He was in a white room and he could hear the beeps of the heart monitor next to him. Suddenly, the events of the past day came flooding back to him. He tried to sit down to check on Sam when he felt a hand on his chest.

Castiel stood right next to Dean, almost watching over him. “Cas?” He asked, his voice frantic. “We gotta get outta here. I gotta find Sam. We gotta-“

Castiel cut him off, shushing his brother gently. “Everything’s going to be fine, Dean,” He said, slowly moving his hand from his brother’s chest. “You took care of me for eighteen years. Now let me take care of you.”


End file.
